CPU usage display with 7-segment LEDs

This one is for the real gadget geeks, or casemodders. I build a display to monitor my CPU. It displays the used percentage of the processor.

If you take a picture with a camera, there is not a lot of things happening on the CPU.


This thing displays how much the CPU of my PC is doing. The value of the CPU usage is read from the PC's register with a Visual Basic script (.exe file). This value is then transmitted via the serial port to an ATmega8 microcontroller. Other nerds will know that this is done via an MAX232 converter. After that I got lazy and decided to use a 7447 (7-segment display driver) to display the result.

It refreshes every second, but that's enough really. It's like the thing you can see when you press CTRL+ALT+DEL. By the way, did you know pressing backspace takes 13% of my CPU...

To do

It works, but there is a lot of things left to do actually. It's clear that I have to get it off the breadboard and onto a PCB. Also the software needs to be cleaned up because it is kind of a mess. Another thing that might be cool is to extend it to 3 or 4 characters and display the temperature of the CPU and the RAM usage. Maybe after that I will build it into my PC. Or in my girlfriend's because hers always lags. =) But I think she will not agree as long as the LEDs are not pink..

If anyone knows where to buy RGB 7-segments, let me know! ;)


Circuit, Visual Basic code for the PC and C code for the microcontroller